A computer system includes several components that are collectively used by a user to perform various functions such as, for example, preparing and generating a document with a word-processing application. Using the computer system, the user may input data to a computing portion using peripheral devices such as a keyboard or a mouse. Data may also be provided to the computing portion using data storage media, e.g., a floppy disk or a CD-ROM. The computing portion, using memory and other internal components, processes both internal data and data provided to the computing portion by the user to generate data needed by the computer system and/or requested by the user. The generated data may be provided to the user via, for example, a display device or a printer.
The computing portion of a computer system typically includes various components such as, for example, a power supply, disk drives, and the electrical circuitry required to perform the necessary and requested operations of the computer system. The computing portion may contain a plurality of circuit boards on which various circuit components are implemented. For example, a computing portion designed to have enhanced sound reproducing capabilities may have a circuit board dedicated to implementing circuitry that specifically operates to process data associated with the reproduction of sound.
On a circuit board, a crystal oscillator provides a reference of time to various integrated circuit (IC) packages that are connected onto the circuit board. Those skilled in the art will recognize that the integrated circuit packages may be used to house and support various types of integrated circuits (e.g., application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), microprocessors, and digital logic chips). The integrated circuit packages communicate with one another, i.e., pass data, using wires or traces of conductive material (e.g., copper or gold) embedded in the circuit board.
Within a computer system, signals between components and devices of the computer system may either be analog or digital. An analog signal takes on continuous values within some range of values and a digital signal has discrete values within some range of values. For example, in a system having a supply voltage of 1V, an analog signal may have a value anywhere between 0V and 1V, whereas a digital signal in the same system might have a value of either 0V or 1V.
Often, it may be necessary to convert between analog and digital values. For example, an analog signal generated by a temperature sensor in a computer system may need to be converted to a digital signal for use by a digital-based integrated circuit. Such conversion may be achieved using an analog-to-digital converter.